Field of the Invention
The present invention relates to a manufacturing method of a honeycomb structure, and more particularly, it relates to a manufacturing method of a honeycomb structure in which it is especially possible to inhibit generation of partition wall cracks during manufacturing of a cordierite honeycomb structure containing a cordierite component.
Description of the Related Art
Heretofore, honeycomb structures made of ceramics have been used in broad use applications of a car exhaust gas purifying catalyst carrier, a diesel particulate removing filter, a heat reservoir for a burning device, and the like. Here, the honeycomb structure is manufactured by preparing a forming raw material (a kneaded material), desirably extruding the material in the form of a honeycomb by use of an extruder, and further firing a rawly cut, dried and end-face finished honeycomb formed body at a high temperature.
Especially in recent years, there has been manufactured a cordierite honeycomb structure (hereinafter referred to simply as “the honeycomb structure”) containing a cordierite component constituted of three components of silicon, aluminum, and magnesium.
The cordierite component has characteristics that its thermal expansion coefficient is lower than that of an alumina material and that the cordierite component is excellent in thermal shock resistance and withstanding strength. Therefore, the honeycomb structure is employed in a broad field of the car exhaust gas purifying catalyst carrier and the like.
When manufacturing a ceramics porous body such as the above honeycomb structure, there is performed an operation of adding powder of porous silica or powder of a porous silica-containing mixture (hereinafter generically referred to as “the powder of porous silica” in the present specification) as an inorganic pore former into a forming raw material, kneading the forming raw material, and extruding the kneaded forming raw material (see Patent Document 1).
When the powder of porous silica is used as the inorganic pore former, there is the advantage that it is possible to inhibit generation of carbon dioxide or a toxic gas, as compared with resin powder or carbon powder which has heretofore been used as the inorganic pore former. Furthermore, the powder of porous silica contains a combustible content which is smaller than that of the resin powder or the like, and hence it is possible to shorten a burning time.                [Patent Document 1] WO 2005/090263        